UC Irvine researchers discover a mechanism that controls the identity of stem cells

Irvine, Calif., Dec.7, 2023 – University of California, Irvine, researchers discovered a mechanism that controls the identity of stem cells. When this mechanism fails, embryonic stem cells revert back in time and become totipotent. When a cell becomes totipotent, this rare change enables the cells ability to differentiate into hundreds of cell types, and then go on to form every part of our body. This contrasts with pluripotent stem cells which can divide into various cell types but are unable to become an entire organism solely on their own.

The study, Nuclear RNS catabolism controls endogenous retroviruses, gene expression asymmetry, and dedifferentiation, was published Dec. 7, 2023, in Molecular Cell. 

“In a dish of embryonic stem cells, the majority of stem cells are pluripotent. However, one out of 1,000 cells are different from the rest, and are totipotent,” said Ivan Marazzi, PhD, director of the Center for Epigenetics and Metabolism at UCI School of Medicine. “Totipotent cells are the only cells that have unlimited potential and can give rise to all parts of our body. We discovered the mechanism that allows this change from pluripotent to totipotent.”

The ability to change the identity of stem cells allows researchers to delve into the fundamental aspect of development, specifically what happens when two cells meet and give rise to an embryo. Moreover, many disorders like cancer and neurodegenerative disease are characterized by cells “going back in time,” a process called cellular dedifferentiation.

“Factors that control this ’reversion’ from stem cell to totipotent cell are mutated in humans with cancer and neurodegenerative disease,” said Marazzi, professor in the Department of Biological Chemistry at UCI School of Medicine.” We think there is a special susceptibility of brain and cancer cells to be vulnerable to this mechanism, which could help us in the future as we treat patients with these conditions.”

The study was funded by the NIH and UCI.

About the UCI School of Medicine

Each year, the UCI School of Medicine educates more than 400 medical students and nearly 150 PhD and MS students. More than 700 residents and fellows are trained at the UCI Medical Center and affiliated institutions. Multiple MD, PhD and MS degrees are offered. Students are encouraged to pursue an expansive range of interests and options. For medical students, there are numerous concurrent dual degree programs, including an MD/MBA, MD/MPH, or an MD/MS degree through one of three mission-based programs: the Health Education to Advance Leaders in Integrative Medicine (HEAL-IM), the Program in Medical Education for Leadership Education to Advance Diversity-African, Black and Caribbean (PRIME LEAD-ABC), and the Program in Medical Education for the Latino Community (PRIME-LC). The UCI School of Medicine is accredited by the Liaison Committee on Medical Accreditation and ranks among the top 50 nationwide for research. For more information, visit medschool.uci.edu.